It is the perennial question in Indian personal finance: when you have a surplus of Rs 5 lakh sitting in your savings account and a home loan running at 8.25%, should you prepay the loan or invest the money in equity mutual funds? The answer, as with most financial decisions, depends on the interplay of interest rates, tax benefits, investment returns, and your personal risk appetite.
The Case Study Setup
Consider Rahul, a 35-year-old salaried professional in the 30% tax bracket under the old regime. He has a home loan of Rs 50 lakh at 8.25% for 20 years, taken in January 2025. His current EMI is Rs 42,614. After 13 months of repayment, his outstanding principal is approximately Rs 48.75 lakh. He has a surplus of Rs 5 lakh and wants to deploy it optimally. Let us model both scenarios: prepaying the loan versus investing in an equity SIP.
Scenario 1: Prepaying the Home Loan
If Rahul makes a lump-sum prepayment of Rs 5 lakh, his outstanding principal drops to Rs 43.75 lakh. Keeping the EMI constant, the loan tenure reduces from the remaining 227 months to approximately 199 months — a saving of 28 months. The total interest saved over the remaining tenure is approximately Rs 5.84 lakh. The effective return on the Rs 5 lakh prepayment, measured as interest saved, works out to roughly 9.2% annualised on a pre-tax basis.
However, Rahul must account for the tax benefit he loses. Under Section 24(b), interest paid on a home loan for a self-occupied property is deductible up to Rs 2 lakh per annum. If Rahul is already claiming close to this limit, the prepayment reduces his interest outgo and thereby reduces his tax deduction. In the 30% bracket, this means the effective cost of his loan is not 8.25% but approximately 5.78% post-tax, assuming he utilises the full Section 24(b) benefit.
Scenario 2: Investing in Equity Mutual Funds
If Rahul invests the Rs 5 lakh as a lump sum in a diversified equity mutual fund, historical data from the last 10 years shows that large-cap funds have delivered a CAGR of approximately 12.5%. Over 19 years (the remaining loan tenure), Rs 5 lakh compounding at 12.5% grows to approximately Rs 48.8 lakh. Even accounting for long-term capital gains tax at 12.5% on gains above Rs 1.25 lakh, the post-tax corpus would be around Rs 43.5 lakh.
The risk, of course, is that equity returns are not guaranteed. In adverse market conditions — a prolonged bear market or a structural economic slowdown — the 10-year return could be as low as 8-9%, at which point prepayment would have been the better choice. Market volatility also means the value of the investment could decline by 30-40% in any given year, which can cause significant psychological stress.
The Hybrid Approach: The Optimal Answer
The mathematically optimal strategy for most borrowers is a hybrid approach. Allocate 40-50% of the surplus (Rs 2-2.5 lakh) to loan prepayment and invest the remainder in a diversified equity SIP. The prepayment provides a guaranteed, risk-free return equivalent to your loan interest rate, while the equity investment captures the higher long-term growth potential. This approach also preserves some of the Section 24(b) tax benefit by not fully eliminating the interest component too early.
For borrowers in the new tax regime, where the Section 24(b) deduction is capped at Rs 2 lakh for self-occupied property and is not available for let-out property, the calculus shifts in favour of prepayment. Without the tax shield, the effective loan cost remains the full 8.25%, making prepayment more attractive compared to the uncertainty of market-linked returns.
Use the prepayment benefit calculator to model your specific loan parameters and see exactly how much tenure reduction and interest saving a given prepayment amount would deliver. The numbers are often more compelling than people expect, particularly in the early years of the loan when the interest component of each EMI is at its highest.
Source
Home loan amortisation data; AMFI mutual fund return data 2016-2026; Section 24(b) and 80C provisions